Synergistic interfacial effect of polymer stabilized graphene via non-covalent functionalization in poly(vinylidene fluoride) matrix yielding superior mechanical and electronic properties

Abstract

Polythiophene-graft-poly(methyl methacrylate) (PT-g-PMMA) functionalized non-covalently with reduced graphene oxide(RGO) (PFG) is used to make composites with poly(vinylidene fluoride) (PVDF), designated as PRPx where x represents PFG content(wt%). RGOs are distributed homogenously in PVDF matrix. FTIR spectra indicate 90% piezoelectric β-polymorph in PRP5. Thermal studies exhibit small decrease of PVDF crystallinity, accelerated crystallization, and enhanced thermal stability. Increase in glass transition and other relaxation temperatures and a maximum (60%) increase of storage modulus are noticed. PRP1 exhibits increment of tensile strength and strain of 317% and 302% over PVDF. Young's modulus varies with PFG following Halpin–Tsai equation for random distribution. The dc-conductivity exhibits percolation threshold at 0.24 vol% PFG with maximum conductivity of 7 × 10−3 Scm−1. The dielectric permittivity also exhibits sharp increase with a maximum of 446.0 at 102 Hz for PRP5. A comparison of the present data with other PVDF composites with covalently functionalized RGO dictates its supremacy.